Allow axolotls to teleport to the player

Axolotls (20w51a) work as companions to the player in combat. They are not pets though, as they follow around players who are holding their favorite food (tropical fish), the same as most passive mobs do. This leading mechanic works just fine when making farms, but it doesn't really translate that well to combat scenarios.

You see, when travelling the ocean, axolotl followers will attack pretty much anything that moves (including fish), completely distracting them from actually following the player. They get left behind and start wandering, eventually getting lost. This can be quite annoying. Pets don't really have this problem, because they can teleport to the player when they get too far away.

I suggest making it so that when an axolotl finds a player who is holding a tropical fish, they become "interested" in that player, and keep following them around until the notice they are no longer holding that fish. While they are interested in a player, they have the ability to teleport to them when they get too far away, the same as pets do.

This would let a player explore the ocean, and get back home with their axolotl army intact (assuming they don't die).